Roll films are applied in the packaging industry mainly because the cost of the entire packaging process can be saved. When roll films are applied in automatic packaging machines, package manufacturers do not need to do any sealing works, but only need to do one-time sealing operation. Emergence of roll films simplifies the entire plastic packaging process into three steps of printing, transportation and packaging, thus greatly simplifying the packaging process, and reducing costs in the whole industry.
Currently, automatic packaging film is formed by coextrusion-laminating two or three layers of materials. OPP, CPP, PE, PET, PP, PVC, aluminum-coated foil, pure aluminum foil, coated paper, etc. of different specifications can be combined as required by customers for production and processing. The main film substrates of compound bags include outer printable film BOPA BOPET BOPP, inner heat-sealable film CPP PE and coextruded film. Generally, the above mentioned materials, as middle layers, are laminated through adhesive into laminated film.
In the past production process, each complete package requires to laminate film of two different materials and then attach a two-side adhesive tape and a one-side adhesive tape between the two materials. The production process has disadvantages that the technological process is complex and inefficient, the adhesive tapes easily get detached, film jamming and breakage and machine shutdown easily occur in the automatic packaging process, and thus automatic packaging fails.